xref: /aosp_15_r20/external/sandboxed-api/sandboxed_api/sandbox2/buffer.h (revision ec63e07ab9515d95e79c211197c445ef84cefa6a)
1*ec63e07aSXin Li // Copyright 2019 Google LLC
2*ec63e07aSXin Li //
3*ec63e07aSXin Li // Licensed under the Apache License, Version 2.0 (the "License");
4*ec63e07aSXin Li // you may not use this file except in compliance with the License.
5*ec63e07aSXin Li // You may obtain a copy of the License at
6*ec63e07aSXin Li //
7*ec63e07aSXin Li //     https://www.apache.org/licenses/LICENSE-2.0
8*ec63e07aSXin Li //
9*ec63e07aSXin Li // Unless required by applicable law or agreed to in writing, software
10*ec63e07aSXin Li // distributed under the License is distributed on an "AS IS" BASIS,
11*ec63e07aSXin Li // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12*ec63e07aSXin Li // See the License for the specific language governing permissions and
13*ec63e07aSXin Li // limitations under the License.
14*ec63e07aSXin Li 
15*ec63e07aSXin Li #ifndef SANDBOXED_API_SANDBOX2_BUFFER_H_
16*ec63e07aSXin Li #define SANDBOXED_API_SANDBOX2_BUFFER_H_
17*ec63e07aSXin Li 
18*ec63e07aSXin Li #include <cstddef>
19*ec63e07aSXin Li #include <cstdint>
20*ec63e07aSXin Li #include <memory>
21*ec63e07aSXin Li 
22*ec63e07aSXin Li #include "absl/status/statusor.h"
23*ec63e07aSXin Li 
24*ec63e07aSXin Li namespace sandbox2 {
25*ec63e07aSXin Li 
26*ec63e07aSXin Li // Buffer provides a way for executor and sandboxee to share data.
27*ec63e07aSXin Li // It is useful to share large buffers instead of communicating and copying.
28*ec63e07aSXin Li // The executor must distrust the content of this buffer, like everything
29*ec63e07aSXin Li // else that comes under control of the sandboxee.
30*ec63e07aSXin Li class Buffer final {
31*ec63e07aSXin Li  public:
32*ec63e07aSXin Li   ~Buffer();
33*ec63e07aSXin Li 
34*ec63e07aSXin Li   Buffer(const Buffer&) = delete;
35*ec63e07aSXin Li   Buffer& operator=(const Buffer&) = delete;
36*ec63e07aSXin Li 
37*ec63e07aSXin Li   // Creates a new Buffer that is backed by the specified file descriptor.
38*ec63e07aSXin Li   // The Buffer takes ownership of the descriptor and will close it when
39*ec63e07aSXin Li   // destroyed.
40*ec63e07aSXin Li   static absl::StatusOr<std::unique_ptr<Buffer>> CreateFromFd(int fd);
41*ec63e07aSXin Li 
42*ec63e07aSXin Li   // Creates a new Buffer of the specified size, backed by a temporary file that
43*ec63e07aSXin Li   // will be immediately deleted.
44*ec63e07aSXin Li   static absl::StatusOr<std::unique_ptr<Buffer>> CreateWithSize(size_t size);
45*ec63e07aSXin Li 
46*ec63e07aSXin Li   // Returns a pointer to the buffer, which is read/write.
data()47*ec63e07aSXin Li   uint8_t* data() const { return buf_; }
48*ec63e07aSXin Li 
49*ec63e07aSXin Li   // Gets the size of the buffer in bytes.
size()50*ec63e07aSXin Li   size_t size() const { return size_; }
51*ec63e07aSXin Li 
52*ec63e07aSXin Li   // Gets the file descriptor backing the buffer.
fd()53*ec63e07aSXin Li   int fd() const { return fd_; }
54*ec63e07aSXin Li 
55*ec63e07aSXin Li  private:
56*ec63e07aSXin Li   Buffer() = default;
57*ec63e07aSXin Li 
58*ec63e07aSXin Li   uint8_t* buf_ = nullptr;
59*ec63e07aSXin Li   int fd_ = -1;
60*ec63e07aSXin Li   size_t size_ = 0;
61*ec63e07aSXin Li };
62*ec63e07aSXin Li 
63*ec63e07aSXin Li }  // namespace sandbox2
64*ec63e07aSXin Li 
65*ec63e07aSXin Li #endif  // SANDBOXED_API_SANDBOX2_BUFFER_H_
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